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Thursday, March 21, 2013

Nudge Database

Update: Here is the latest version of the Nudge Database pdfThis is
a list of empirical ‘nudges’ and their sources with a particular emphasis on
those sourced from academic papers. It will be updated regularly. I
created it because while there are many interesting papers and websites
documenting nudges, there is a lamentable absence of any searchable, central
database. If you know of some nudges that I have not included, please let me
know by email or Twitter. The nudges listed here are intended
as a quick reference: if you are looking for sample sizes and p-values you need
to check the original paper. Where possible I have provided links to freely
accessible versions of the papers.Part I|| Part II|| Part III|| Part IV|| Part V || Part VI || Part VII || Part VIII || Part IX || Part X

1. Nudge: Using defaults in organ donation
to increase compliance rates. Those countries where people are required to
opt-out of organ donation report significantly higher consent than those with an
opt-in policy. Possibly
the most famous nudge, certainly the most eye-catching.Tags : Defaults / Organ donation / opt-in
opt-out

2. Nudge: The authors
sought to prime honesty by asking
people to sign at the start of a form rather than the end when reporting how
many miles they had driven on their car for insurance purposes.

In this
case there was a financial incentive to report less miles driven since
reporting more would mean you would pay more (i.e. a higher number in the graph
implies more honesty). The results indicated the
treatment to be effective at inducing more honest declarations.

3.Nudge: General Electric wanted its
employees to stop smoking. They
submitted to a Randomized Control Trial where the treatment group received cash incentives to quit. The control
group received no incentives. Quitting for 6 months earned you $250, quitting
for 12 months $400.

The
treatment group had 3 times the success rate of the control (14.7% gave up smoking vs 5%), even after
financial incentives were discontinued after 12 months (9.4% vs 3.6%). On the strength of this
finding, GE now does this for their 152,000 employees.Tags : Smoking / financial incentives /
health

4. Nudge: The ‘Save More Tomorrow’ [SMarT]
program used defaults to increase
employees’ savings rates by
automatically increasing the % of their wage devoted to saving. Average saving
rates for SMarT program participants increased from 3.5% to 13.6% over the
course of 40 months. This is one of the most famous nudges. Tags : defaults / saving / save more
tomorrow

Source: Benartzi & Thaler (2004), ‘Save More Tomorrow’, Journal of Political Economy.5.Nudge: The Behavioral Insights Team in
the U.K. used social normative messages
to increase taxcompliance in 2011. The control group received standard tax
letters. The treatment groups received the letters with an added normative
messages.The difference in compliance
rates between the control and the most effective treatment group was 15 percentage points.

6.Nudge: A Randomized Controlled Trial
using social normative messages to
increase publican license renewals in
Ireland. Similar to the work of the BIT, the control group received a standard
renewal letter. The treatment group received a simplified letter which included
a social normative message. After 1 year the treatment group had 35.5% renewal
rates, the control had 29.4%.Tags : social norms/ compliance / pub licenses

Source: Walsh, K. [2012, unpublished]

7.Nudge: Using personalized text messages for collecting fines, as per the picture. This is a very nice use of salience. The most effective treatment in this case included using the person’s name and specifying
how much they owed compared to a control of receiving a letter notifying them that they owed money.

Personalization in policy is an interesting area. Cass Sunstein, co-author of 'Nudge' believes that "personalized defaults are the way of the future". Sunstein says "it is increasingly possible for private and public institutions to
produce highly personalized default rules, which reduce the problems
with one-size-fits-all defaults. In principle, personalized default
rules could be designed for every individual in the relevant population."Tags : salience / tax compliance /
Behavioural Insights Team

8.Nudge: A Randomized Controlled Trial
that used lotteries to encourage weight loss. Very well designed in
terms of behavioral principles.

In
the treatment group, a person steps on the scales in the morning. The subject’s
weight is calculated & sent to a server comparing it to his weight-loss
goals. The subject receives an email about his weight and a text message
regarding the daily lottery. Success in meeting weight-goals enters the subject
into a daily lottery with a 20% chance of winning $10 & a 1% chance of
$100. If one doesn’t meet their goal, they are still entered in the lottery.
But if they win, they are notified by text what
they could have won, a clever use of regret aversion as motivational tool.

9.Nudge: Encouraging stroke victims to take their warfarin pills via lotteries. Designed in reactance to the
serious issue of patients not taking their medicine correctly.

The treatment
group had a 1% chance of winning $100 contingent upon taking their pills
correctly.The control group did not
have any incentives to take their pills correctly beyond the threat of dying.
Adherance in the treatment group was almost 100% compared to 80% in the control
[though with the caveat that the sample size is very small, n=10] . Findings like this support the argument that more
should be spent on behavioral research in health-care. Dr. David Halpern of the
Behavioral Insights Team has noted that in Lord Darzi’s 2008 report on the
NHSbehavioral research currently
receives less than 0.5% of medical research spending in the U.K.

10.Nudge: The Behavioural Insights Team ran
a 6 month Randomized Controlled Trial with Jobcentre Plus in Essex to test the
impact of several changes to the way the centre operates, specifically through commitment devices & emphasis on
building psychological resilence. They found job seekers in the treatment group
15-20% more likely to be off benefits 13 weeks after signing on.

11. Nudge: The
American electricity company Opower use socialnormative messages comparing a
person’s electricity usage to that of their neighbours to reduce electricity consumption. This is an area with interesting
diversity of findings. Schultz et al (2007) found the use of normative messages
with injunctive emoticons effective at reducing consumption. Allcott (2011)
estimates this program reduces consumption by around 2% for Opower’s customers.

Interestingly,
Costa & Kahn [2010] found this kind of normative nudge may backfire with
political conservatives, who may actually increase their electricity
consumption in reactance to it.

12 comments:

Cristina Raboj
said...

Great job!

Not sure if it fits very well in the 'nudge' list, but here's an interesting finding. In charitable giving, seed money are the funds received prior to eliciting donations from the public. In a field experiment, List and Lucking-Reiley [2002] found that increasing the seed money from 10% to 67% of the campaign goal produced a nearly sixfold increase in contributions. The authors posit that seed money (1) signal charity credibility and reliability and (2) stand as social proof. I noticed Wikipedia does the same when they ask for donations.

The paper is called: 'The effects of seed money and refunds on charitable giving: Experimental evidence from a university capital campaign', by List and Lucking-Reiley [2002].

Hey Mark, Do you think reducing the hot-cold empathy gap (Loewenstein) could be seen as a nudge that fits in your list? I just thought about why removing trays in cafeterias (http://www.nytimes.com/2009/04/29/nyregion/29tray.html) leads to less food waste and thought that if people have a tray they base their decision about how much food to take on their visceral state of hunger before they have eaten anything. Without trays they make this decision of how much to take in steps and always with an 'updated state' of hunger.

I'd like to include the hot-cold empathy gaps but so far I haven't found a nudge that addresses them specifically. Did you know Loewenstein and his handsome mustache are coming to Stirling in September for a talk?http://www.stir.ac.uk/events/calendarofevents/siresymposium/

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The purpose of this blog is to provide a forum for discussing research in microeconomics, behavioural economics and cognate areas. This blog is not affiliated to any institution and all posts represent personal views and opinions of the individual posters. The blog is moderated by Liam Delaney